Showing papers in "Experimental Biology and Medicine in 1948"
TL;DR: A strain of staphylococci in becoming resistant to penicillin did not show an increase in its resistance to sulfactin and the increase in resistance developed by a strain of E. coli to streptomycin was intermediate.
Abstract: SummaryA strain of staphylococci in becoming resistant to penicillin did not show an increase in its resistance to sulfactin. A similar strain of staphylococci in becoming resistant to sulfactin di...
1,941 citations
TL;DR: A differential sheep cell agglutination test is described wherein the agglUTination titers of human serum for normal and sensitized sheep erythrocytes are compared.
Abstract: SummaryA differential sheep cell agglutination test is described wherein the agglutination titers of human serum for normal and sensitized sheep erythrocytes are compared. High differential titers have been found to occur almost solely with the sera of patients suffering from active rheumatoid arthritis. Some of the features of this serological phenomenon are pointed out, together with its possible practical applications.
545 citations
TL;DR: The tendency of injected porphyrin and metalloporphyrins to accumulate in lymph nodes may limit the therapeutic usefulness of these compounds in all neoplastic diseases except lymphatic leukemias.
Abstract: Summary and ConclusionsThese experiments show that all porphyrins tested accumulate in neoplastic (induced and transplanted sarcomas, spontaneous and transplanted mammary carcinomas), embryonic and regenerating tissues. Introduction of a metal (zinc) into the porphyrin molecule did not destroy the tendency of the porphyrin to concentrate in tumors. The tendency of injected porphyrins and metalloporphyrins to accumulate in lymph nodes may limit the therapeutic usefulness of these compounds in all neoplastic diseases except lymphatic leukemias. The possibility of using small doses of radioactive metalloporphyrins for detecting deep cancer is being investigated.
343 citations
TL;DR: A strain of Bacillus subtilis has been isolated which elaborates a previously undescribed antibiotic “Bacillomycin” which possesses striking antifungal activity and almost complet...
Abstract: SummaryA strain of Bacillus subtilis has been isolated which elaborates a previously undescribed antibiotic “Bacillomycin.” This antibiotic possesses striking antifungal activity and almost complet...
265 citations
TL;DR: When acted upon by streptomycin, certain strains of Euglena gracilis undergo a permanent loss of chlorophyll, without being inhibited in growth if good energy and carbon sources are supplied to make up for the loss of photosynthesis.
Abstract: SummaryWhen acted upon by streptomycin, certain strains of Euglena gracilis undergo a permanent loss of chlorophyll, without being inhibited in growth if good energy and carbon sources are supplied to make up for the loss of photosynthesis. The degree of exposure to streptomycin. Proliferating and non-proliferating cells, and cells exposd in the light and in the dark, appear equally susceptible to bleaching.
160 citations
TL;DR: Sarcomas were induced in albino fats by the insertion of regenerated cellulose film either subcutaneously or by wrapping it around one kidney by means of cellophane, a simple method for inducing sarcomas experimentally.
Abstract: Conclusions1. Sarcomas were induced in albino fats by the insertion of regenerated cellulose film either subcutaneously or by wrapping it around one kidney.2. These tumors occurred in about 35% of ...
153 citations
TL;DR: The histochemical distribution and properties of choline esterase are described and it is possible to demonstrate them histo-chemically by incubating slides with the substrate in the presence of a cobalt salt.
Abstract: SummarySome choline esterases hydrolyze higher choline esters readily and they also survive to a demonstrable extent the procedures of histological fixation and embedding. It is possible to demonstrate them histo-chemically by incubating slides with the substrate in the presence of a cobalt salt; at the sites of choline esterase activity insoluble cobalt-soap will precipitate which can be transformed into black CoS. The histochemical distribution and properties of choline esterase are described.
128 citations
TL;DR: Conventional histological techniques have been modified so that it is possible consistently to cut 0.2 micron sections for use with the electron microscope, and micrographs of rat liver sections show that the principal artefacts are due to fixation rather than subsequent treatments.
Abstract: SummaryConventional histological techniques have been modified so that is is possible consistently to cut 0.2 micron sections for use with the electron microscope. The material must be doubly embedded in strong collodion and hard paraffin. The face of the block to be cut must be small, and the tilt of the knife must be precisely adjusted.Procedures have been developed for partly or wholly removing the embedding media, and mounting the sections for the electron microscope.Micrographs of rat liver sections show that the principal artefacts are due to fixation rather than subsequent treatments.
124 citations
TL;DR: The ease of performance and the rapidity with which clear-cut results are obtained, make the toxoplasmin skin test the most useful single aid in the diagnosis of past or latent toxoplasmosis, wherever isolation of the caustive organism is not feasible.
Abstract: SummaryThe preparation of toxoplasmin, a skin testing antigen made of toxoplasma has been described. Toxoplasmin evokes reactions of a delayed (tuberculin) type of hypersensitivity in certain patie...
108 citations
TL;DR: A colorimetric method based on the reaction of tryptophane with carbohydrates is described for the determination of serum non-glucosamine polysaccharide, which obeys the Lambert-Beers law within the limits investigated.
Abstract: SummaryA colorimetric method based on the reaction of tryptophane with carbohydrates is described for the determination of serum non-glucosamine polysaccharide. The absorption maximum for the carbohy-drate-tryptophane compound is at 500 mμ for galactose and for mannose, 460 mμ for glucose, and 520 m//, for fructose. Glucuronic acid, glucosamine, and hemoglobin have maxima at wave lengths below 400 mμ. Glucuronic acid also exhibits a weak band at 480-500 mμ.The absorption curves for alcohol precipitates from serum, ascitic fluid, and hydrocele fluid differ from postulated galactose-mannose-glucosamine curves by showing greater absorption in the 400-480 mμ, range. This difference diminishes when the polysaccharide is partly freed from protein.Hemolysis, if marked, introduces a positive error in the method. The color produced by the carbohydrate tryptophane reaction obeys the Lambert-Beers law within the limits investigated.
82 citations
TL;DR: The present data are insufficient to define the mechanisms involved in the secretory process or to demonstrate the relative magnitude of the processes of filtration, reabsorption and secretion in the renal excretion of K.
Abstract: Discussion and ConclusionsK clearances in excess of creatinine or thiosulfate clearances, under the conditions of these experiments, are interpreted as- evidence that all of the K excreted in the urine cannot be accounted for by the nltration-reabsorption theory alone, but that tubular secretion of K also occurs. In the experiments on urea diuresis, urea clearances never exceeded creatinine clearances, and the ratios agreed with the observations of Shannon.8 It is a reasonable hypothesis that during urea diuresis the secretion of K becomes apparent because its normal tubular reabsorption is hindered. The present data are insufficient to define the mechanisms involved in the secretory process or to demonstrate the relative magnitude of the processes of filtration, reabsorption and secretion in the renal excretion of K. Further work is in progress.
TL;DR: Choline caused reabsorption of aortic atherosclerosis in the majority of rabbits whose lesion had been produced by cholesterol feeding.
Abstract: ConclusionsCholine caused reabsorption of aortic atherosclerosis in the majority of rabbits whose lesion had been produced by cholesterol feeding.
TL;DR: The presence of a tubular secretory mechanism located, presumably, in the distal tubule has been demonstrated by the intravenous administration of hypertonic KC1 solutions which yielded rates of potassium excretion considerably above the rates of filtration of potassium at the glomerulus.
Abstract: Summary and ConclusionsA constant rate of potassium excretion, dissociated from filtered load, occurring after salyrgan administration suggested a tubular secretory mechanism located, presumably, in the distal tubule. The presence of such a mechanism has been demonstrated by the intravenous administration of hypertonic KC1 solutions which yielded rates of potassium excretion considerably above the rates of filtration of potassium at the glomerulus.
TL;DR: The volume of distribution of inulin has been determined by a priming dose and a constant intravenous infusion to insure uniform distribution throughout the extracellular space, followed by collection of the total inulin excreted in the urine after the infusion is discontinued.
Abstract: SummaryThe volume of distribution of inulin has been determined by a priming dose and a constant intravenous infusion to insure uniform distribution throughout the extracellular space, followed by collection of the total inulin excreted in the urine after the infusion is discontinued. The inulin space in the dogs ranges from 20.9 to 23.2% of the body weight (average 21.6) and in man from 15 to 16%, as compared with larger spaces obtained with thiocyanate, bromide and sodium.
TL;DR: The lytic action was found to be due to the presence of desoxyribonuclease which is elaborated during the growth of strains of hemolytic streptococci and is freely demonstrable in the fluid medium in which the organisms are cultivated.
Abstract: SummaryIn experiments in which the following substrates were employed: 1) specimens of purulent exudations from patients, 2) desoxyribose nucleoprotein isolated from the exudates and, 3) desoxyribo...
TL;DR: Desoxyribose nucleoprotein has been identified as a significant constituent of purulent and inflammatory exudates derived from patients and its physical characteristics of stringiness, viscidity, and coagulated gel, indicate its significance in contributing to the sedimented elements of exudations.
Abstract: SummaryDesoxyribose nucleoprotein has been identified as a significant constituent of purulent and inflammatory exudates derived from patients. Its chemical characteristics have been described and it has been isolated in quantities ranging from 30 to 70% of the total purulent sediment.Its physical characteristics of stringiness, viscidity, and coagulated gel, indicate its significance in contributing to the sedimented elements of exudations. Protein-free desoxy-ribonucleic acid has been derived from the nucleoprotein.The liquefaction of both the nucleoprotein and the nucleic acid has been found to occur following the addition of beef desoxyribonuclease and preparations of hemolytic streptococcal filtrates containing desoxyribonuclease,.By the Feulgen method of staining the abundance of desoxyribose nucleoprotein in exudates has been demonstrated microscopically.
TL;DR: A histochemical method for the demonstration of sites of phosphamidase activity is described, finding large amounts of the enzyme found in the grey matter of the central nervous system and in malignant epithelial tumors.
Abstract: SummaryA histochemical method for the demonstration of sites of phosphamidase activity is described. Small amounts of the enzyme are present in many normal tissues; large amounts are found in the grey matter of the central nervous system and in malignant epithelial tumors.
TL;DR: In young growing rats, the same substances do not produce endosteal bone but interfere with endochondral ossification by inhibiting resorption of cartilage matrix and new bone.
Abstract: SummaryEstrogenic steroid hormones stimulate endosteal bone formation and inhibit bone resorption in mice. In young growing rats, the same substances do not produce endosteal bone but interfere with endochondral ossification by inhibiting resorption of cartilage matrix and new bone. In other rodents, such as hamsters, guinea pigs, and rabbits, and also in cats and dogs, there is no apparent specific effect of estrogens upon formation of bone.
TL;DR: Inoculation of embryonated eggs with toxoplasma resulted in a generalized parasitic disease of this host with a fatal termination and the agent could be maintained by serial passage of embryo brain.
Abstract: SummaryInoculation of embryonated eggs with toxoplasma resulted in a generalized parasitic disease of this host with a fatal termination. The agent could be maintained by serial passage of embryo brain. Chorioallantoic membranes from infected eggs contained a stable, specific soluble antigen which fixed complement with toxoplasma immune animal serum. Human sera from both proven and suspected cases of toxoplasmosis which were known to contain neutralizing antibody against the parasite also fixed complement with chorioallantoic membrane antigen.
TL;DR: Evidence that virus disease may develop a latent state is reviewed with an account of the reports of successful activations of latent infections and19 instances of precipitation of latent herpetic infection in rabbits by anaphylactic shock.
Abstract: Summary1. Evidence that virus disease may develop a latent state is reviewed with an account of the reports of successful activations of latent infections.2. Nineteen instances of precipitation of latent herpetic infection in rabbits by anaphylactic shock are presented.3. Recovery of Herpes simplex virus from rabbit central nervous system during periods of (a) quiescence, (b) chronic encephalitis, (c) spontaneous exacerbations, and (d) anaphylactically induced precipitations of encephalitis is reported.
TL;DR: Pantothenic acid has been demonstrated to be an essential metabolite for Trichomonas vaginalis and a requirement for phosphate has been established.
Abstract: Conclusions1. Pantothenic acid has been demonstrated to be an essential metabolite for Trichomonas vaginalis. 2. A requirement for phosphate has been established. 3. A culture medium containing a greatly reduced number of components has been developed for routine use.
TL;DR: The electrophoretic mobility of human type O erythrocytes was found to decrease from 1.32 to 0.5-0.6 μ/sec./v./cm in the presence of 0.311 to 16.9 μg/ml of a highly purified preparation of the PR8 strain of influenza virus.
Abstract: ConclusionsThe electrophoretic mobility of human type O erythrocytes was found to decrease from 1.32 to 0.5-0.6 μ/sec./v./cm in the presence of 0.311 to 16.9 μg/ml of a highly purified preparation of the PR8 strain of influenza virus.Adsorption and elution of the virus, and agglutination of the erythrocytes was found to be concurrent with the decrease in electrophoretic mobility of the erythrocytes.The time of intimate contact of virus with cells and the pattern of decrease of electrophoretic mobility are not only interdependent but also dependent upon the concentration of added virus.At the optimal ratio of virus to erythrocytes, as determined by the mobility and titration curves, it has been calculated that only 1/80 of the erythrocytic surface is covered by virus particles and that this value corresponds to about 298 PR8 virus particles to one erythrocyte.
TL;DR: Significant eosinopenia has been observed following injection of epinephrine and of insulin in patients with essential hypertension and patients with adrenal or pituitary insufficiency.
Abstract: SummarySignificant eosinopenia has been observed following injection of epinephrine and of insulin. This change was exaggerated in patients with essential hypertension, and diminished or absent in patients with adrenal or pituitary insufficiency. Marked eosinopenia has been found after surgical operations.
TL;DR: A synthetic mixture is described which has the same properties of restoring the dialysed media and the most important of its components seem to be glutamine and fructose-diphosphate.
Abstract: Summary1. The difference between growth-promoting substances and accessory growth substances and between their different modes of action is pointed out. 2. From dialysates from embryo juice, preparations may be obtained which completely restore the ability of the dialysed culture media to induce normal growth of the tissue cultures. They may be prepared free from organic phosphates and glutamine. 3. A synthetic mixture is described which has the same properties of restoring the dialysed media. The most important of its components seem to be glutamine and fructose-diphosphate.
TL;DR: The intravenous injection of meningococcal or Salmonella endotoxin into rabbits produced increase in blood glucose, lactic acid and inorganic phosphorus and this was followed by hypoglycemia which could be observed before the death of the animal.
Abstract: Summary The intravenous injection of meningococcal or Salmonella endotoxin into rabbits produced increase in blood glucose, lactic acid and inorganic phosphorus. This was followed by hypoglycemia which could be observed before the death of the animal. Liver and muscle glycogen decreased while lactic acid content of the tissues increased. The pyruvic acid content of blood and tissues showed a significant decrease. Succinic dehydrogenase in both muscle and liver was markedly inhibited. Cytochrome oxidase activity was not affected.
TL;DR: Testicular damage was not found in experiments in which infra red irradiation was applied for 10 minutes at 38°C but was observed when applied at a temperature of 40°C and above and the type of degeneration resulting from microwave exposure could not be distinguished from that produced by infraRed.
Abstract: SummaryA study was made concerning the effects of 12 cm electromagnetic waves and of infra red irradiations upon the testes of adult albino rats. A single ten-minute exposure to microwaves at a temperature of 35°C as measured in the central areas of the testes caused testicular degeneration in all cases. In some experiments testicular damage resulted from a single exposure at temperatures between 30° and 35°C. Testicular damage was not found in experiments in which infra red irradiation was applied for 10 minutes at 38°C but was observed when applied at a temperature of 40°C and above. The type of degeneration resulting from microwave exposure could not be distinguished from that produced by infra red.
TL;DR: The serum polysaccharide was lowest in the fetal group and highest in the aged representatives, the children and young adult groups being intermediate, thus showing a tendency to increase with age, and Concentrations of serum poly Saccharide for young adults were significantly higher than those of fetal serums, and significantly lower than for the aged.
Abstract: Summary and ConclusionsStudies of serum polysaccharides were made on a total of 66 normal persons including fetal, children, young adult, and aged representatives.The serum polysaccharide (both non-glucosamine and glucosamine) was lowest in the fetal group and highest in the aged representatives, the children and young adult groups being intermediate, thus showing a tendency to increase with age.Concentrations of serum polysaccharide (both non-glucosamine and glucosamine) for young adults were significantly higher than those of fetal serums, and significantly lower than for the aged. The total protein for young adults was significantly higher than in fetal sera. Significant positive correlations were found between non-glucosamine polysaccharide and total protein and also between non-glucosamine polysaccharide and glucosamine.In the same individual, non-glucosamine serum polysaccharide and glucosamine were subject to about the same variation as serum protein over a period of sixteen months. Small variation...
TL;DR: The transfer of sensitivity by injection of whole blood taken with other observations suggests that the white cells of the circulating blood may participate more widely than previously believed in immunological phenomena.
Abstract: Summary1. In confirmation of Chase's studies, the tuberculin type of hypersensitivity has been transferred passively to normal, unsensitized guinea pigs by injection of the cells of peritoneal exudate, lymph nodes, spleen, and whole blood of tuberculin-sensitive guinea pigs. The passively conferred sensitivity lasted 4 or 5 days.2. The transfer of sensitivity by injection of whole blood taken with other observations suggests that the white cells of the circulating blood may participate more widely than previously believed in immunological phenomena.3. The positive results employing suspensions containing 95% of lymphocytes suggest that this cell type may be of great importance in the transfer of sensitivity.
TL;DR: Evidence is presented that suggests the disappearance not only of prothrombin in dogs treated with dicumarol, but also of a factor important in the conversion of prostrombin to thrombin, which is associated with the plasma pseudoglobulins, but unlike prothromabin it is plentiful in serum.
Abstract: SummaryEvidence is presented that suggests the disappearance not only of prothrombin in dogs treated with dicumarol, but also of a factor important in the conversion of prothrombin to thrombin. Like prothrombin, this factor is associated with the plasma pseudoglobulins, but unlike prothrombin it is plentiful in serum. Addition of plasma, serum or serum pseudoglobulin corrects the delayed prothrombin convertibility of early dicu-marolization or of stored plasma. The discrepancy between the one-stage and 2-stage methods of estimating prothrombin seems to reside in this conversion factor.
TL;DR: The gastric secretory response to a standard dose of histamine in dogs with a totally isolated stomach pouch is markedly reduced by bilateral vagotomy, and gastric vagotomy in patients with peptic ulcer also markedly reduces the gastricsecretory response.
Abstract: Conclusions1. The gastric secretory response to a standard dose of histamine in dogs with a totally isolated stomach pouch is markedly reduced by bilateral vagotomy.2. Atropine similarly reduces the gastric secretory response to histamine in these animals.3. Gastric vagotomy in patients with peptic ulcer also markedly reduces the gastric secretory response to a standard dose of histamine.